1. Field of the Invention
The present invention relates to a lever operation device suitable for use as, for example, a turn signal switch device or a wiper switch device of an automobile.
2. Description of the Related Art
Lever operation devices used as turn signal switch devices or wiper switch devices of automobiles generally include a columnar operation lever that projects from a housing fixed to, for example, a steering column. The operation lever can be pivoted along two operation planes that are substantially orthogonal to each other. The operation lever is selectively operated along the individual operation planes, and a plurality of types of operation signals are output in accordance with the direction in which the operation lever is operated.
A known support structure of an operation lever in a lever operation device of this type includes a holder that supports a base portion of the operation lever such that the base portion is pivotable along a first operation plane; a first driver that is in elastic contact with a first cam surface provided on an inner back wall of the holder; a housing that supports the holder such that the holder is pivotable along a second operation plane that is substantially orthogonal to the first operation plane; a second driver that is in elastic contact with a second cam surface provided on an inner back wall of the housing; and detecting means capable of individually detecting the pivoting operations of the operation lever along the first and second operation planes, and the first and second drivers are arranged substantially on a single straight line (see, for example, Japanese Unexamined Patent Application Publication No. 2001-6494).
In the lever operation device according to the related art having the above-described structure, when a user operates the operation lever along the first operation plane, the operation lever pivots with respect to the holder and the housing. In response to this operation, the first driver slides along the first cam surface to generate a clicking sensation, and one of slide switches included in the detecting means is driven and turned on by the base portion of the operation lever. When the user operates the operation lever along the second operation plane, the operation lever pivots together with the holder with respect to the housing. In response to this operation, the second driver slides along the second cam surface to generate a clicking sensation, and the other one of the slide switches included in the detecting means is driven and turned on by the holder.
However, in the above-described lever operation device according to the related art, the first driver that is in elastic contact with the inner back wall of the holder and the second driver that is in elastic contact with the inner back wall of the housing are arranged substantially on a single straight line, so that a desired clicking sensation is generated when the operation lever is operated along the first or second operation plane. Accordingly, there is a problem that it is difficult to reduce the size of the support structure of the operation lever. In other words, according to the example of the related art, a mechanism for supporting the base portion of the operation lever such that desired operations can be performed is necessarily long in the depth direction. Thus, it is difficult to reduce the size of the lever operation device.